Setting Isolation level using CFTRANSACTION AND ORM EntityLoad - sql-server

Question

I am working with ColdFusion 9 and MS SQL Server.
I am trying to use:
<cftransaction isolation="read_uncommitted">
<cfset X = EntityLoad('table',row_id,true)>
</cftransaction>
to change the isolation level in some transactions
but looking on the log from the datasource I got this:
09:20:32.688)>> Connection[6].prepareStatement(String sql)
09:20:32.688)>> sql = select ..... _ID=?
09:20:32.688)>> OK (PreparedStatement[871])
09:20:32.689)>> PreparedStatement[871].executeQuery()
09:20:33.594)>> OK (ResultSet[989])
09:20:33.606)>> Connection[6].setTransactionIsolation(int level)
09:20:33.606)>> level = 1
09:20:33.962)>> OK
09:20:34.141)>> Connection[6].setTransactionIsolation(int level)
09:20:34.141)>> level = 2
09:20:34.501)>> OK
If replace the EntityLoad for a simple cfquery call I get this:
09:24:30.164)>> Connection[6].setTransactionIsolation(int level)
09:24:30.164)>> level = 1
09:24:30.519)>> OK
09:24:30.519)>> Statement[37].execute(String sql, int autoGeneratedKeys)
09:24:30.519)>> sql = select ...
09:24:30.519)>> autoGeneratedKeys = 1
09:24:30.699)>> OK (true)
09:24:30.879)>> Connection[6].setTransactionIsolation(int level)
09:24:30.879)>> level = 2
09:24:31.234)>> OK
So it seems that when I use ORM's EntityLoad the isolation level is not set correctly.
Does anyone knows why? And what would be a better way to set isolation levels using ORM?

Answer 1

I found a post about this on the ColdBox blog by Curt Gratz: Coldfusion ORM - Transaction Isolation Level... Read that post in it's entirety, it has some good points. But basically Curt found that you can create a custom hibernate config file to specify various settings.
From that blog post:
So, since changing the isolation level isn't one of the settings available in the ormsettings, I had to create a custom hibernate config file.
At first I thought this would be difficult as I thought that I would have to insert all the "standard" settings the Coldfusion implementation of hibernate was already using, but it turns out, you only have to set any additional properties you wish to use. Here is a list of available hibernate configuration options.
http://docs.jboss.org/hibernate/core/3.3/reference/en/html/session-configuration.html
So, on to some code...
Here is my newly created hibernate config file.
<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD//EN"
"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<!-- a SessionFactory instance listed as /jndi/name -->
<session-factory
name="java:hibernate/SessionFactory">
<!-- properties -->
<property name="connection.isolation">1</property>
</session-factory>
</hibernate-configuration>
Notice one thing in the config file. <property name="connection.isolation">1</property>. Why one you ask...
Here is the int values for each of the isolation levels available.
java.sql.Connection
public static final int TRANSACTION_NONE 0
public static final int TRANSACTION_READ_COMMITTED 2
public static final int TRANSACTION_READ_UNCOMMITTED 1
public static final int TRANSACTION_REPEATABLE_READ 4
public static final int TRANSACTION_SERIALIZABLE 8
Source: http://java.sun.com/j2se/1.5.0/docs/api/constant-values.html#java.sql.Connection.TRANSACTION_READ_COMMITTED
Then in my application.cfc I set
<cfset this.ormsettings = {dialect="MicrosoftSQLServer", ormconfig="hibernate.xml"}>
Now, be sure that you have your hibernate.xml file somewhere outside of webroot to protect it from being read by any evil eyes.
There you go, hope this helps you as it took me a lot of digging to figure it out
Full credit to Curt Gratz for this information.
Re-posted here in case that page is removed in the future.